As crude oil demand increases rapidly by fast progress of industry at recent years, oil exploration is lively performed, and crude oil transportation increases rapidly. Accordingly, an accident at sea by an oil outward flow would frequently occur. As a result, fishes may fall dead and birds are fatally damaged. In addition, habitat of birds may decrease. Further, the soil and ocean may be polluted by exploration and drilling. The soil and ocean are gradually severely polluted by a malicious outward flow of industrial waste as well as an accident of leakage and rupture of oil pipage or storage tanks.
A number of oil adsorbents and oil adsorption methods have been developed for such problem solution. There are hundreds of oil adsorbents which are currently used. The oil adsorbents are classified into ones for preventing oil pollution of the ocean or recovering the soil polluted by oil, according to use. According, to ingredients of oil adsorbents, the oil adsorbents are classified into an inorganic adsorbent of porous mine such as zeolite, illite, and perlite, and clayey bentonite having a large swelling property, a natural oil adsorbent of a vegetable property having a good porous adsorption capability such as shell of pine trees, the contents of African millet and corn, waste pulp, trunk of sedge, sawdust, and the chaff, and an adsorbent of a polymeric material such as particles, fibers, and non-woven cloths, which are made of polyethylene, polyprophylene, or polystyrene, a surface active agent and a surface active agent composite, and the above-described oil adsorbents, alone or in combination thereof. Besides, there is an oil adsorbent for recovering the soil in which an oil decomposition microbial medicine prepared from microbes is combined with the oil adsorbent, to thus enable biodegradation of the soil biologically.
In particular, the oil adsorbents for preventing ocean pollution among the above-described adsorbents are formed by adsorbing or infiltrate a surface active agent or surface active agent composite into an inorganic adsorbent or vegetable property adsorbent mainly, to then be spread in an oil pollution area of the sea to adsorb the contaminated oil. However, the particles of the oil adsorbent are sunk on the underwater ground floor at the state where the oil adsorbent adsorbs and emulsifies oil, to thus cause a secondary pollution on the ground floor. As being the case, part of the adsorbed oil is leached by water pressure and floated on the sea. In addition, a hydrocarbon adsorbent made of a composition polymer such as polyethylene and polypropylene has a good adsorptive power, but it takes long to adsorb the polluted oil. The hydrocarbon that is adsorbed by an outer surface tension is not adsorbed perfectly, but part of oil bubbles is leached.
In addition, a method of purifying underground water that has been polluted by organic matters by use of organic clay is introduced in the Korean patent publication No. 10-2006-0068163. In the Korean patent publication No. 10-2006-0068163, an adsorbent which adsorbs organic pollution materials which are made by adsorbing a surface active agent to a clay mineral, is put into the polluted underground water, to thus adsorb the organic pollution materials. Then, the organic pollution materials are separated from the underground water. Accordingly, the underground water that has been polluted by organic matters is purified by use of organic clay.
In the case of the above-described method of purifying underground water that has been polluted by organic matters by use of organic clay, it is extremely difficult to separate and remove the oil adsorbent of the powder or particle state into which oil has been adsorbed from the underground water. In addition, it is possible to perform an oil adsorption work in a small-scale limited area, but it is not possible to perform an oil adsorption work for a bulky ocean pollution.
Besides, a method of manufacturing an oil adsorbent using peat moss whose oil adsorption is superexcellent and an oil adsorption method using the oil adsorbent, are introduced recently.
As as example, a biological biodegradation adsorbent for removing oil and the other hydrocarbon compound and a method of manufacturing the same is introduced in the Korean patent registration No. 10-0455754. In the Korean patent registration No. 10-0455754, the biological biodegradation adsorbent and the method of manufacturing the same are used for soil recovery of the soil which has been polluted by oil or hydrocarbon, in which a surface active agent is added to peat moss, and the surface active agent added peat moss is dried to have a moisture content of 7-8 wt %, and then a microbial medicine prepared from microbes is inoculated into and fixed to a matrix (medium: elvan powder). That is, the matrix is added to the biological biodegradation adsorbent.
The biological biodegradation adsorbent is used for recovery of the soil which has been polluted by hydrocarbon including oil, but it is difficult to use it in the vast sea. Although the biological biodegradation adsorbent may used for preventing ocean pollution, the biological biodegradation by microbes is ineffective or meaningless. In addition, the particles which is formed by adding a surface active agent to peat moss or elvan powder has an oil adsorption function. However, the above-described particles or elvan powder may sink on the bottom of the sea after oil adsorption, which may cause a secondary pollution on the ground floor.
Besides, a method of manufacturing an adsorption filter which uses peat moss as a main material is introduced in the Korean patent publication No. 1997-0061320. In the adsorption filter manufacturing method, peat moss is put into a kiln and maintained at 300° C., to thus reduce a moisture content to be simultaneously carbonated into about 50% or so. Accordingly, the property of the peat moss is formed into a porous capillary tube fibroid material. In addition, a biological recovery method of recovering soil polluted by oil by use of peat moss is introduced in the Korean utility-model registration No. 20-0348451. In the Korean utility-model registration No. 20-0348451, a fertility index and an acidity of soil are measured, and then a nutrient, alkali (quicklime or calcium carbonate), and a peat moss adsorbent are added to the soil according to the measured result, to thus recover the soil polluted by oil into the soil from which oil is removed. Accordingly, the biological recovery method is not proper as a method of adsorbing and removing oil polluted on the sea.